Method and apparatus for conditioning gas



11, 1964 E. w. SIMONS METHOD AND APPARATUS FOR CONDITIONING GAS Filed Aug. 24, 1960 F/6. Z

3 Sheets-Sheet 2 INVENTOR. EDWARD SIMONS A T TORNEVS 3 Sheets-Sheet 5 INVENTOR. EDWARD S/MOA/S HAWW AT TOR/V5 VS United States Patent 1 O 3,143,952 METHOD AND APPARATUS FOR CONDITIONING GAS Edward W. Simons, San Francisco, Calif., assignor, by direct and mesne assignments, to Dualjet Corporation, a corporation of California Filed Aug. 24, 1960, Ser. No. 51,717 8 Claims. (Cl. 98-36) This invention relates to a method and apparatus for forming and maintaining diiferent characteristics in the gaseous content in different fixed portions of an enclosed space, and is similar in some respects to that shown in United States Patent No. 2,862,369, dated December 2, 1958. In the cited patent a method and apparatus was disclosed for providing an air conditioned display compartment having a horizontally directed open sidethrough which access could be had to the interior of the compartment. The patent described in detail a display device the interior of which was refrigerated for the storage of food products although the invention was not limited to temperature control. p

The present invention is also concerned with the provision of an air conditioned space and offers certain improvements applicable to the disclosure of the cited patent. In addition the present invention extends the scopeof the principles set forth in the cited patent and discloses a method and apparatus for providing different character istics in air or the like within contiguous communicating spaces. The difference in the characteristics within various spaces as contemplated by the present invention may be due to a difference in temperature, humidity, oxygen content, or any other characteristic of air capable of being varied, or it may be due to a difference in two or more of such characteristics. l

The term matrix climate as used herein designates the climate or the atmospheric or other gaseous layer surrounding the spaces having controlled gaseous characteristics and need not necessarily be the ambient climate. Such matrix climate would enter the spaces within which a desired gaseous condition is maintained if no means were used to exclude it. I

The main object of the present invention is, therefore,

the provision of improved means for providing and maintaining a desired gaseous condition in a space having an open side communicating with an adjacent space having a different climate condition. y h I Another object of the invention is the provision of a method and apparatus for providing different character- 'istics in the air or gas in communicating spaces. An example might be the provision of a refrigerated space divided into two separate communicating compartments with the temperature in each compartment being different for the storage of different kinds of goods. In such :a case anair curtainmay be employed to isolate the perature compartment would be interposed between the matrix climate and the compartment, of lowest tempera ture for greatest efficiency. If a third refrigeratedcom- 'partment at a still lower temperature were desired, it would be the most remote from the matrix .climate.

It will be understood, of course, that temperature is only one of severalvariables contemplated by the invention which may be controlled to effect different character- 'istics.

Still another object of the invention is the provision of 'a method and apparatus for establishing difierent characteristics in the gas or air in communicating spaces and j at the same time providing means for adjusting the condientrainment.

tion to be controlled so that close regulation of the particular characteristic involved may be readily effected.

Yet another object of the invention is to improve the eificiency of air curtains of the type shown in Patent 2,862,369 by making the air flow more laminar and by minimizing turbulence. This object is attained by novel design of the nozzles from which the air curtain jets emanate. A

Other objects and advantageswill be apparent from the following specification and the drawings:

FIG. 1 is a semischematic top plan view of a structure and apparatus for effecting different characteristics in three communicating spaces which are surrounded by a matrix climate.

FIG. 2 is a plan view similar to FIG. 1 but showing a modified form wherein a door opening is provided with an air curtain of which the air for the jets is taken from the spaces adjacent the jets.

FIG. 3 is cross section through a. spaceshowing a different duct arrangement from FIG. 1.

FIG. 4 is a side elevation of a pair of nozzles.

FIG. 5 is an enlarged cross section of a pair of jet nozzles showing the orientation of the nozzles to enhance laminar flow.

In detail, and with reference first to FIG. 1, the invention contemplates broadly the provision of a plurality of contiguous communicating spaces such asthose indicated at A, B and C. Naturally, more or. less spaces may be provided without deviating from the invention.-

The spaces A, B, C are surrounded by another, space D (FIG. 1) which may be considered to contain a matrix climate. To form the various spaces a pair of, sidewalls 1, 2, an endwall 3, and a suitable top or ceiling (not shown) are provided. The side of the structure opposite endwall 3 is open as are the common sides of the spaces A, B, C. Thus the plane 4 indicated by a dot-dash line in FIG. 1 may be considered to be the dividing plane between the matrix climate D and the microclimate A.

The characteristics in; areas A, B, C are sustained. by

means of air curtains disposed along the open sides of the respective spaces. Thus, the air curtain between spaces D and A consists of jets 10, 11 disposed on opposite sides of plane 4 and, as noted in PatentNo. 2,862,369 hereinbefore referred to, jets 10, 11 travel in the same direction and have substantially the same speed so that a minimum amount of entrainment between said jets takes place. Preferably the flow of air constituting jets 10, 11 should be perfectly laminar, as any turbulence or deviation of the air from straight line flow tends to produce The condition of the air in jet 11 should be about the same as the condition of the air in A while jet 10 may be composed of air taken from matrix climate D. Assuming that air at A is to be maintained at alower temperaturethan matrix climate D, jet 11 may be designated 'as a primary jet and jet 10 may be considered to be it is desired to promote in air at A. If it were desired to maintain air at A at a higher temperature than matrix climate D, the terms guard jet. and primary jet would still apply just as they would if some other character istic, for example, oxygen content were-to be enhanced in air at A.

It will be understood that if air at A is to be maintained 'at a lower temperature than matrix climate D, it is necessary to continuously cool the air. in space A to make up for heat transferred thereto by radiation and leakage. This may be conveniently accomplished by providing 3 cooling coils 12 within the duct 13 which conducts air to primary jet 11. One method of accomplishing the desired air flow is shown schematically in FIG. 1 wherein duct 13 is provided along the sidewall 1 and terminates in a nozzle generally designated 15. The detailed structure of nozzle 15 will be described in detail later on.

Within duct 13 there may be provided a conventional air moving fan 16 for moving the desired volume of air and an obstruction 17 is preferably provided adjacent nozzle 15 to increase the velocity of the air emanating from said nozzle. At this point it may be noted that the velocity of air in jets 10, 11 need not be so high as to cause discomfort to a person exposed to them. Velocities as low as 250 feet per minute may be used.

The air from primary jet 11 may be recirculated through a duct 20 extending alongside sidewall 2 and a fan 21 may be provided in said duct 20 for this purpose. Air from primary jet 11 enters duct 20 through a protective -grill 22 and is discharged from duct 20 through a nozzle 23 to form a guard jet 24 cooperating with the primary jet 25 of space B. Air from guard jet 24 enters duct 13 through a protective grill 26 to complete the recirculation. 7

Although the air in guard jet 10 in matrix climate D may be conditioned, if desired, by the arrangement of FIG. 1, the air is simply taken from matrix climate D and moved by fan 28 through nozzle 29 alongside plane 4 toward a receiver 30. It will be understood that the air of guard jet 10 may be recirculated or simply discharged into matrix climate D.

The above described structure in space A may be duplicated for space B as indicated and, if a third space such as C is employed, the same structure applies except that the air may be returned by a duct 32 to the primary jet. There is thus provided a guard jet 34 in space B and a primary jet 35 in space C acting to separate spaces B, C

along the plane 6.

The operation and advantages of the arrangement shown in FIG. 1 may best be understood by assuming that it is desired to retain space C at a relatively low temperature, space B at a somewhat higher temperature, and space A at a still higher temperature and yet lower than the temperature of matrix climate D. If no cooling coils are employed to condition the air in spaces A, B, it will be apparent that the desired differences in climate in the spaces may be achieved by refrigerating the air in space C only by means of cooling coils 37. Because of heat exchange due to radiation and leakage there will exist a temperature gradient between space C and matrix climate D with the temperature in space B being higher than that in space C and lower than space A.

In order to permit variation in temperature in the different communicating spaces, swingable mixing blades such as indicated at 38, 39 (FIG. 1) may be provided at the outlet sides of nozzle 23 in space A and nozzle 40 in space B. By swinging said blades as indicated, entrainment between jets 24, 25 may be promoted by intentionally creating turbulence and air movement through plane 5 so that the temperature in spaces A, B may be adjusted as desired. Similarly the relative temperatures of spaces B, C may be adjusted.

Another method of intentionally causing mixing of air between contiguous spaces is to change the speed of one fan to create a difference in velocity between the guard jet and primary jet. In this manner the condition of equal velocities on which nonentrainment depends is destroyed and mixing results.

The above-described preferable arrangement of different gaseous characteristics follows the thermodynamic principle of heat flow from a high temperature to a low temperature sink and provides optimum etficiency. Thus,

referring to FIG. 1., heat flow is from matrix climate D across the jet curtain formed by guard jet 10 and primary jet 11 to air or gas at A, across the jet curtain formed by guard jet 24 and primary jet 25 to air or gas 4 at B, across the jet curtain formed by guard jet 34 and primary jet 35 to air or gas at C.

If condition permit, it is possible, as explained above, to permit cooling coils 37 to carry the full load, but the desired differences in temperature may also be achieved by providing cooling coils for each of the spaces such as coils 12 in space A and coils 42 in space B. Such an arrangement permits closer adjustment and greater flexibility in establishing the exact characteristic desired.

Naturally the foregoing description of the principles involved would apply in the same manner if it were desired to maintain the gas or air at C at a higher instead of a lower temperature than in the other areas A, B. In this latter case the heat flow would, of course, be reversed. Coils 12a, 37a and 42a are heating coils which may be used for accomplishing this reverse heat flow or in combination with cooling coils 12, 37 and 42 for conditioning the various curtains as to humidity. Furthermore, the same principles would apply if it were desired to maintain air at C at a relatively high oxygen content for example. In such a case it would merely be necessary to supply oxygen to space C to make up for leakage.

It will be apparent that the particular method of recirculating the air is not critical. In FIG. 2 an arrangement is shown where areas or spaces X, Y, Z are sep arated by partitions 45, 46 so as to form door openings, the central planes 47, 48 of which define the boundaries of the areas or spaces. It will be noted that the particular jets are simply discharged into their associated spaces and no ducts are employed for recirculation. In such a case it is, of course, still necessary to condition the air in each space to achieve the characteristic desired.

FIG. 3 is a section looking from wall 3 to area C toward area B showing a modified form of ductwork which obviates the low level horizontally extending ducts of FIG. 1. In FIG. 3 primary jet 35 is received in inlet 51 and directed upwardly by turning vanes 52 to an elevated duct 53 which conducts the air longitudinally of the space to a transverse duct 57 positioned along wall 3 and then to a longitudinally extending duct 54 from which the air is directed downwardly through turning vane 55 to outlet nozzle 56.

By this structure ducts 53, 54 are of sufficient length to accommodate whatever coils and fans are required and these ducts and transverse duct 57 are raised high enough olf the floor level so that the usable space in the compartment is not impaired.

FIG. 4 shows a pair of nozzles 56, 58 which may be similar to nozzle of FIG. 3. These nozzles are provided with a plurality of relatively small passageways extending longitudinally of the air flow to reduce turbulence and promote laminar flow. Such passageways may be formed by a grid with the dimensions between the sides of the passageways being sufiiciently small to insure such laminar flow. Unless the flow is laminar the distance which the jets can be thrown without causing turbulence is considerably reduced.

By the present invention two principles are followed to reduce turbulence to a minimum and increase the throw of the jets. First, laminar flow is insured by design of the nozzles in a manner to be described and, second, the dual jets which form each air curtain are directed convergently to minimize turbulence.

Referring now to FIG. 5, a pair of nozzles 60, 61 are shown which are each formed with a plurality of passageways 62. Said passageways may be in the form of tubes or slots or in the shape of a grid. It has been found that the length of each passageway should be between certain limts calculated with reference to the applicable Reynolds number. For laminar flow a Reynolds number less than 2100 should apply computed on the basis of an equivalent pipe or duct with an hydraulic diameter equivalent to four times the hydraulic radius. The hydraulic radius is defined as the cross sectional flow area divided by the wetted perimeter.

It has been found that to achieve the desired type of flow in the air curtain jets the length of the nozzle passage or tube should be between the limits of one half the minimum passageway width times a factor varying from the square root of the Reynolds number to one-third of the Reynolds number.

For example, if a Reynolds number of 300 is desired, a passageway having at least a dimension of A?" should be at least 1" long and should not exceed about 6" in length. Thus:

It has also been found that laminar flow in a dual jet curtain of the type herein contemplated is enhanced by causing two jets to converge slightly at the point of discharge. Thus, as shown in FIG. 5, the nozzles 60, 61 are arranged on opposite sides of a wedge-shaped divider :63 so that the included angle between the nozzles is from about 14 to 24. The pair of swingable dampers 38, 39 may be positioned alongside the outer sides of the jets so as to adjust the jet and, if desired, to promote entrainment as described above. Between the two jets a mixing blade 64 may also be provided for the same purpose. That is, it may be used to assist in achieving laminar flow in the contiguous jets or it may be rotated, as indicated by the dotted line position, to promote entrainment as desired.

By the above-described invention it is possible to control to a considerable extent the leakage past an air curtain of the type shown in Patent 2,862,369 and achieve the desired difierent conditions with an amount of power that is within a practical range. eifect separation of spaces by means of air curtains thus obviating doors and walls.

The very specificatic arrangement given above of the preferred form of the invention should not be taken as restrictive of the invention as it will be apparent that various modifications in design may be resorted to without departing from the invention as defined in the following claims.

I claim:

1. The method of conditioning the gaseous content of a pair of adjoining areas that comprises the steps of;

(a) Simultaneously moving a first gas and a second gas in a pair of separate endless paths that extend away from each other enclosing said adjoining areas with the gas in one of the sides of said paths being in planar layers in parallel, engaging, opposed relation whereby a characteristic of the gas in one path of said pair will be transmitted to the gas in the other path and the gaseous content of the areas enclosed by said paths will partake of such characteristic;

(b) conditioning said first gas to have a predetermined characteristic that is of a greater intensity than that of any corresponding characteristic of said second gas whereby gaseous content of the area enclosed by the gas of said second path will have said last-mentioned characteristic but to a lesser degree of intensity than the gaseous content of the area enclosed by said first path.

2. The method of differently conditioning the gaseous content of different adjoining areas within a space the gaseous content of which is similar in all of said areas, comprising the steps of;

(a) moving gas in a series of endless paths providing adjoining pairs of said paths respectively enclosing said adjoining separate areas within a space of predetermined size having a similar gaseous content,

(b) formng the gas in the adjacent sides of each adjacent pair of paths to provide a gaseous curtain and partition of a pair of parallel, substantially planar gaseous layers in said paths in contact with each other Also, it is possible to separating the gas in the areas enclosed within said paths from each other whereby a characteristic of one gaseous layer of each adjoining pair will partake of the characteristic of the other layer for transmission of such characteristic to the gaseous content of the area enclosed by the gas within each path;

( c) causing the gas in said paths to move in the same direction in the portions forming each pair of adjoining layers whereby the gas within each of the areas within said space will be retained within each of said areas against movement past each of said gaseous curtains;

(d) conditioning the gas in one of said paths to have a predetermined characteristic adapted to be transmitted to the gas in the adjoining path through contact of the gas in the adjoining path at the adjoining layers forming a curtain for transmission of said characteristic to the gaseous content in the area enclosed by said adjoining path.

. (e) confining the gas within the portion of each area extending to each of said layers against contact with the atmospheric air.

3. Air discharge means for forming a substantially flat gaseous curtain from a pair of flat contiguous jets of gas in opposed, side-by-side relation and moving in the same direction comprising;

(a) a pair of discharge nozzles each having. a passageway provided with a pair of opposed parallel flat sides for forming the opposite sides of each curtain, and each formed with an elongated discharge opening at one end of said passageway.

(b) means supporting said nozzles with their discharge openings parallel and adjacent to each other and with the pair of parallel sides of one nozzle extending slightly divergently relative to the parallel sides of the other nozzle in a direction away from said discharge openings, so that the included angle between planes parallel with the respective parallel sides of said nozzles will be from about 14 degrees to 24 degrees whereby the gas discharged from said discharge openings will form contiguous substantially parallel fiat jets of gas to provide said flat, gaseous curtain,

(0) separate conduits respectively communicating with said nozzles for supplying gas to one nozzle having a characteristic that is different from the gas adapted to be supplied to the other nozzle.

4. In air discharge means as defined in claim 3.

(d) a plurality of relatively thin, parallel, spaced dividers in side-by-side relation within each of said passageways parallel with the said flat sides thereof and (e) separate means adjacent to one of the sides of each of said discharge openings supported for movement to difierent gas deflecting positions relative to the gas adapted to be discharged from said openings for selectively deflecting the gas discharged from said openings laterally relative to planes respectively parallel with the said opposite sides of each of said passageways whereby the gas discharged from said openings may be deflected to entraining relation.

5. The method of differently conditioning the gaseous content within different areas within a space that is enclosed against direct communication with atmospheric air but that is surrounded by the latter, comprising the steps of:

(a) simultaneously moving a pair of adjoining, substantially parallel, opposed layers of gas in the same direction across said space to provide a gaseous partition between and in contact with the gaseous content of the areas within said space at opposite sides of said partition with one layer of said pair thereof bounding and in contact with one side of the gaseous content of the area at one side of said partition and with the other layer of said pair thereof bounding and in contact with one side of the gaseous content of the area at the other side of said partition;

(b) circulating the gas of said layers in separate endless paths;

(c) conditioning said layers prior to said movement thereof across said space to have different charaeteristics distinguishing them from said atmospheric air and from each other whereby the gaseous content of each of said areas will partake of the characteristic of the gaseous layer in contact therewith and will have characteristics differing from each other and from said atmospheric air.

6. In a compartment having an opening in one side thereof:

(a) a pair of air outlet nozzles extending across one side of said opening having discharge openings directed toward the opposite side of said opening and adapted to discharge air in the form of a pair of air curtains across said opening extending to said opposite side thereof;

(b) a pair of air inlets along said opposite side of said opening directed toward said outlet nozzles;

(c) means for circulating air along a pair of separate paths respectively communicating between each inlet and one of said nozzles for discharge of said air curtains across said opening;

(d) means in one path of said pair for conditioning the air therein to distinguish it from the air in the other path,

(2) said pair of outlet nozzles extending convergently in a direction toward their discharge openings at such an angle to each other as to direct the curtains of air issuing therefrom at an angle to each other into merging relation to form a continuous air curtain with the air at each side thereof having substantially the characteristic as the air respectively discharged at each of said discharge openings.

'7. In a construction as defined in claim 6.

(f) the included angle of convergence between said nozzles being approximately from 14 to 24.

8. In refrigerated compartment having an opening in one side thereof for viewing the contents of said compartment and for providing access to the latter;

(a) a pair of parallel outlet nozzles extending across one side of said opening having elongated parallel discharge openings extending the length of said one side;

(b) a pair of corresponding inlets extending across the opposite side of said opening directed toward said discharge openings;

(c) means for continuously moving a pair of curtains of air from said outlet nozzles to said inlets across said opening with the inner curtain next to the interior of said compartment being colder than the curtain remotefrom said interior;

(d) means for so refrigerating the air of said inner curtain prior to discharge thereof from one nozzle of said pair,

(e) said nozzles extending convergently in direction toward said discharge openings and substantially in engagement along at their convergent ends along a medial line extending longitudinally of and between their discharge openings for discharging said curtains of air therefrom at a slight angle to each other at said medial line, whereby said curtains will engage each other at an angle substantially immediately upon discharge from said openings for movement of said curtains across said opening in continuous contiguous engaging relation from said discharge openings to said inlets.

References Cited in the file of this patent UNITED STATES PATENTS 983,877 Cummings Feb. 14, 1911 2,034,231 Fox Mar. 17, 1936 2,794,325 Shearer June 4, 1957 2,855,760 Simons Oct. 14, 1958 2,862,369 Simons Dec. 2, 1958 2,863,373 Steiner Dec. 9, 1958 2,935,925 DOoge May 6, 1960 3,010,379 Arzberger Nov. 28, 1961 3,021,776 Kennedy Feb. 20, 1962 FOREIGN PATENTS 481,991 Great Britain Mar. 22, 1938 

1. THE METHOD OF CONDITIONING THE GASEOUS CONTENT OF A PAIR OF ADJOINING AREAS THAT COMPRISES THE STEPS OF; (A) SIMULTANEOUSLY MOVING A FIRST GAS AND A SECOND GAS IN A PAIR OF SEPARATE ENDLESS PATHS THAT EXTEND AWAY FROM EACH OTHER ENCLOSING SAID ADJOINING AREAS WITH THE GAS IN ONE OF THE SIDES OF SAID PATHS BEING IN PLANAR LAYERS IN PARALLEL, ENGAGING, OPPOSED RELATION WHEREBY A CHARACTERISTIC OF THE GAS IN ONE PATH OF SAID PAIR WILL BE TRANSMITTED TO THE GAS IN THE OTHER PATH AND THE GASEOUS CONTENT OF THE AREAS ENCLOSED BY SAID PATHS WILL PARTAKE OF SUCH CHARACTERISTIC; (B) CONDITIONING SAID FIRST GAS TO HAVE A PREDETERMINED CHARACTERISTIC THAT IS OF A GREATER INTENSITY THAN THAT OF ANY CORRESPONDING CHARACTERISTIC OF SAID SECOND GAS WHEREBY GASEOUS CONTENT OF THE AREA ENCLOSED BY THE GAS OF SAID SECOND PATH WILL HAVE SAID LAST-MENTIONED CHARACTERISTIC BUT TO A LESSER DEGREE OF INTENSITY THAN THE GASEOUS CONTENT OF THE AREA ENCLOSED BY SAID FIRST PATH. 